The really inexplicable thing is that cigarettes are completely legal for adults, although the CDC reports that smoking causes more than 480,000 deaths each year.
Meanwhile, marijuana is broadly criminalized even though not a single person has died from an overdose of marijuana.

Marco Rubio was born in 1971 at Cedars of Lebanon Hospital in Miami, Florida, making him a U.S. citizen by birth according to the 14th Amendment.
The nonsensical birther argument that he is ineligible is premised upon a willful misreading of Article II which states that "No person except a natural born Citizen ... shall be eligible to the Office of President." The thing is, he was born in the United States and gained citizenship by being born in the United States. He is a natural born citizen -- as everyone outside the tinfoil hat brigade understands.

civics: the study of the rights and duties of citizens and of how government works.Civics classes are hardly a new idea. Generations of American school children were taught civics as a routine part of their education.
Your concern that schools might use civics classes as an opportunity to propagandize children is well taken, but that problem is far from unique to civics classes. On balance, education is preferable to ignorance.